Real-time non-stationary flowmeter

Abstract

The invention concerns a system for real-time measurement of the instantaneous flow rate of a fluid with steady or unsteady flow in a conduit, comprising a flow member ( 1 ) for the fluid provided with at least two wall pressure taps (A,B), means ( 2 ) to measure pressure difference coupled with the two pressure taps (A,B), and programmed computing means ( 3 ) for real-time computing of flow rate by solving a nonlinear, ordinary, differential equation relating instantaneous flow rate to pressure difference, the pressure difference in said formula being positive or negative in relation to the variation in flow velocity of the fluid in the conduit and/or to the direction of flow of the fluid, characterized in that the flow member ( 1 ) comprises a filter ( 4 ) positioned between the two pressure taps (A,B) to increase pressure drop.

1 . A real-time measurement system of the instantaneous flow rate of a fluid with steady or unsteady flow in a conduit, comprising a flow member ( 1 ) for the fluid provided with at least two wall pressure taps (A,B), measuring means ( 2 ) to measure pressure difference coupled with the two pressure taps (A,B) and computing means ( 3 ) programmed for real-time computing of flow rate by solving a nonlinear, ordinary, differential equation relating instantaneous flow rate to pressure difference, the pressure difference in said formula being positive or negative in relation to the variation in flow velocity of the fluid in the conduit and/or to the direction of flow of the fluid, wherein the flow member ( 1 ) comprises a filter ( 4 ) positioned between the two pressure taps (A,B) to increase pressure drop. 
     
     
         2 . The system of  claim 1 , wherein the flow member ( 1 ) has cylindrical geometrya circular cross-section (S) of constant diameter. 
     
     
         3 . The system of claim, wherein the flow member ( 1 ) has frustoconical geometry of Venturi type. 
     
     
         4 . The system of  claim 1 , wherein the flow member ( 1 ) comprises two additional filters ( 5 , 6 ) respectively arranged upstream and downstream of the flow member ( 1 ) relative to the flow of fluid, so as to condition the flow. 
     
     
         5 . The system of  claim 1 , wherein the filter(s) ( 4 , 5 , 6 ) are arranged substantially perpendicular to the axis of the flow member. 
     
     
         6 . The system according of  claim 1 , wherein the filter(s) ( 4 , 5 , 6 ) are grids. 
     
     
         7 . The system of  claim 1 , wherein the filter(s) ( 4 , 5 , 6 ) have a honeycomb structure. 
     
     
         8 . The system of  claim 1 , wherein the filter(s) ( 4 , 5 , 6 ) are formed in a porous material. 
     
     
         9 . The system according of  claim 1 , wherein the flow member ( 1 ) further comprises one or more temperature measurement probes coupled with the computing means ( 3 ). 
     
     
         10 . The system of  claim 1 , wherein the flow member ( 1 ) further comprises a static pressure measurement probe coupled with the computing means ( 3 ).